
\begin{tikzpicture}
  \tkzDefPoints{0/0/A,6/0/B}
  \tkzDefShiftPoint[A](60:4){C}
  \tkzDefLine[bisector,normed](A,B,C) \tkzGetPoint{b}
  \tkzDefLine[bisector,normed](A,C,B) \tkzGetPoint{c}
  \tkzInterLL(A,C)(B,b) \tkzGetPoint{D}
  \tkzInterLL(A,B)(C,c) \tkzGetPoint{E}
  \tkzInterLL(B,D)(C,E) \tkzGetPoint{O}
  \tkzDrawPolygon(A,B,C)
  \tkzDrawSegments(B,D C,E)
  \tkzMarkSegments[color=teal,mark=|](O,D O,E)
  \tkzDrawPoints(A,B,C,D,E,O)
  \tkzLabelPoints[below](A,B,E)
  \tkzLabelPoints[above](C)
  \tkzLabelPoints[above right](O)
  \tkzLabelPoints[left](D)
\end{tikzpicture}
